Build requirements

You must include the following header files from the
BlackBerry Platform Services (BPS) library:

#include <bps/bps.h>
#include <bps/locale.h>

Discussion

Retrieving the locale settings from the tablet is easy enough - just
initialize the BlackBerry Platform Services library and call the
locale_get() function from the
bps/locale.h library. To listen for changes to locale
settings, you must first register the application to receive locale events.
Once your application has been registered to receive events, you can call
bps_get_event() to retrieve the application's next event.

Once you've retrieved the event, you just need to confirm that it is
in fact a locale event. First, you should verify the domain of the event to
make sure it has the locale domain. Then you need to verify the code for the
event. In this case, you're looking for events of the
LOCALE_INFO type since these events are generated
whenever the current language or country changes. Once you've determined that
this is the event you're looking for, all that's left to do is retrieve the
language and country from the event and respond to the change as you see fit.